Complexity of prefrontal cortical dysfunction in schizophrenia: More than up or down
Complexity of prefrontal cortical dysfunction in schizophrenia: More than up or down
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DOI：
10.1176/appi.ajp.160.12.2209
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发表时间：
2003-12-01
影响因子：
17.7
通讯作者：
Weinberger, DR
中科院分区：
文献类型：
--
作者：
Callicott, JH;Mattay, VS;Weinberger, DR
目的：许多神经影像学研究已经检查了精神分裂症患者背外侧前额叶皮层的功能;尽管通常会发现异常，但尚不清楚为什么有些研究发现激活太少，而另一些则太多。方法：对14例精神分裂症患者和14名健康对照者进行N-back工作记忆任务和3 T功能磁共振成像检查，结果：精神分裂症患者在两背工作记忆任务上的表现明显差于健康对照者。然而，与健康受试者相比，患者的背外侧前额叶皮层中有更活跃的区域，也有不太活跃的区域。当小组被细分的基础上的表现对工作记忆任务的健康受试者和患者的高或低性能，更大的前额叶激活和区域的激活较少的地方被发现在高性能的患者，但只有区域的激活不足被发现在低性能的患者。结论：这些发现表明，在N-back工作记忆任务上的表现与健康对照受试者相似的精神分裂症患者使用更多的前额叶资源，但准确性较低（即，效率低下），而其他精神分裂症患者则无法维持处理信息的前额叶网络，结果准确率甚至更低。这些发现补充了其他证据，表明精神分裂症患者前额叶皮质功能异常不能简单地归结为活动过多或过少，而是反映了处理由背外侧前额叶皮质介导的信息的神经策略受损。
Objective: Numerous neuroimaging studies have examined the function of the dorsolateral prefrontal cortex in schizophrenia; although abnormalities usually are identified, it is unclear why some studies find too little activation and others too much. The authors' goal was to explore this phenomenon.Method: They used the N-back working memory task and functional magnetic resonance imaging at 3 T to examine a group of 14 patients with schizophrenia and a matched comparison group of 14 healthy subjects.Results: Patients' performance was significantly worse on the two-back working memory task than that of healthy subjects. However, there were areas within the dorsolateral prefrontal cortex of the patients that were more active and areas that were less active than those of the healthy subjects. When the groups were subdivided on the basis of performance on the working memory task into healthy subjects and patients with high or low performance, locales of greater prefrontal activation and locales of less activation were found in the high-performing patients but only locales of underactivation were found in the low-performing patients.Conclusions: These findings suggest that patients with schizophrenia whose performance on the N-back working memory task is similar to that of healthy comparison subjects use greater prefrontal resources but achieve lower accuracy (i.e., inefficiency) and that other patients with schizophrenia fail to sustain the prefrontal network that processes the information, achieving even lower accuracy as a result. These findings add to other evidence that abnormalities of prefrontal cortical function in schizophrenia are not reducible to simply too much or too little activity but, rather, reflect a compromised neural strategy for handling information mediated by the dorsolateral prefrontal cortex.